Hello! I'm glad to answer your question. This website is to verify whether the message you want to process comes from WeChat server. When the developer submits the verification application for the first time, the WeChat server will send a GET request to the filled URL with four parameters (signature, timestamp, nonce and echostr). Developers can judge the authenticity of this message by verifying the signature. Since then, every time the developer receives a user message, WeChat will also take the first three parameters (signature, timestamp and nonce) to access the URL set by the developer, and the developer will still judge the authenticity of the message by verifying the signature. The verification method is consistent with the verification application submitted for the first time. The developer verifies the request by verifying the signature (there are verification methods below). If it is confirmed that the GET request comes from WeChat server, please return the echostr parameter content as it is, and the access will take effect, and the developer will succeed, otherwise the access will fail. The encryption/authentication process is as follows: 1. Sort token, timestamp and nonce in dictionary order. 2. Splicing three parameter strings into one string for sha 1 encryption. 3. The encrypted string obtained by the developer can be compared with the signature, indicating that the request originated from WeChat.